Income Taxes (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Effective income tax rate	18.80%	31.90%	34.40%	35.90%
Reversal of tax accruals	$ (3.6)	$ (2.6)
Tax benefit related to charitable contribution	$ (1.0)
ASU 2016-09 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Change in effective income tax rate over prior period	3.60%		1.00%